The present invention relates to a ratchet drive tool of the type using a drive stud for coupling with any of a series of selectable sockets or other workpiece-engaging elements. More particularly, the invention is directed to a drive wrench energized by a non-manual power supply but which may also be safely and effectively used manually.
Drive wrenches which are energized electrically, using batteries or line current supplies, are known in the art. Wrenches such as air-driven impact wrenches using non-manual power such as compressed air and similar energy sources are also well known. For the most part such tools, which rely upon non-manual power source energization, cannot be used advantageously employing manual power alone.
Drive tools of the general type referred to above may incorporate universal joint mechanisms to facilitate ease of access to a bolt or a nut to be tightened or removed. In such devices the applied torque is directed through a drive component which is oriented essentially coaxially with the element of the tool to be driven. Any angle of deviation from an in-line disposition of driving and driven element is necessarily quite limited or restricted. No substantial deviation from coaxial alignment is ordinarily feasible, particularly in a simple arrangement of simple mechanical components. Again, such tools do not lend themselves to the use, optionally, of manual power as a substitute for a non-manual energy source.
Also known in the art are electrically energized tools, including battery driven nut drivers and related tools in which a driving stud or workpiece-engaging element or coupler of the wrench is axially in direct drive alignment with an elongate tool body or hand-gripped housing of the tool. While the body of such tools may be rotated by hand about its elongate axis, coaxially with the mode of rotation effected during battery driven operation, the torque which can be realized in such a manual operation is significantly limited. Such torquing forces which can be impressed by manually rotating the elongate tool are ordinarly insufficient either to break-loose a "frozen" bolt or nut or to tighten or lock fasteners to a required or desired degree of security. Manual rotation of the "shaft" of the tool about its axis is ineffective to develop the required torque.
It is, therefore, a principal aim of the present invention to provide a ratchet drive tool which may be used, optionally, with either non-manual power or manually and in which application of very substantial manual torquing force is feasible as a viable option and is achieved in a simple and effective manner.